KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

Manually perform cache maintenance on the source VM during intra-host
migration to ensure no stale data is left in CPU caches after the VM is
destroyed.  Because the source VM is "converted" to a non-SEV VM, KVM's
memory reclaim flows won't trigger cache maintenance, e.g. when all guest
memory is reclaimed in response to detaching from the mmu_notifier.

Note, relying on the destination VM to do cache maintenance isn't an option
as KVM doesn't require identical guest memory configurations, i.e. the
source VM may have access to memory that the destination VM does not.
Enforcing equivalent memory configurations is infeasible, as it would
require a *deep* comparison of memslots, e.g. to verify that not only are
the memslot identical, but what the memslots point at is also identical.

Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Reported-by: Stefan Teodorescu <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 82 insertions, 0 deletions

diff --git a/drivers/hid/hid-topseed.c b/drivers/hid/hid-topseed.c
new file mode 100644
index 000000000..645e36cd8
--- /dev/null
+++ b/drivers/hid/hid-topseed.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID driver for TopSeed Cyberlink remote
+ *
+ *  Copyright (c) 2008 Lev Babiev
+ *  based on hid-cherry driver
+ *
+ *  Modified to also support BTC "Emprex 3009URF III Vista MCE Remote" by
+ *  Wayne Thomas 2010.
+ *
+ *  Modified to support Conceptronic CLLRCMCE by
+ *  Kees Bakker 2010.
+ */
+
+/*
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#define ts_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
+					EV_KEY, (c))
+static int ts_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+		struct hid_field *field, struct hid_usage *usage,
+		unsigned long **bit, int *max)
+{
+	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_LOGIVENDOR)
+		return 0;
+
+	switch (usage->hid & HID_USAGE) {
+	case 0x00c: ts_map_key_clear(KEY_WLAN);		break;
+	case 0x00d: ts_map_key_clear(KEY_MEDIA);	break;
+	case 0x010: ts_map_key_clear(KEY_ZOOM);		break;
+	case 0x024: ts_map_key_clear(KEY_MENU);		break;
+	case 0x025: ts_map_key_clear(KEY_TV);		break;
+	case 0x027: ts_map_key_clear(KEY_MODE);		break;
+	case 0x031: ts_map_key_clear(KEY_AUDIO);	break;
+	case 0x032: ts_map_key_clear(KEY_TEXT);		break;
+	case 0x033: ts_map_key_clear(KEY_CHANNEL);	break;
+	case 0x047: ts_map_key_clear(KEY_MP3);		break;
+	case 0x048: ts_map_key_clear(KEY_TV2);		break;
+	case 0x049: ts_map_key_clear(KEY_CAMERA);	break;
+	case 0x04a: ts_map_key_clear(KEY_VIDEO);	break;
+	case 0x04b: ts_map_key_clear(KEY_ANGLE);	break;
+	case 0x04c: ts_map_key_clear(KEY_LANGUAGE);	break;
+	case 0x04d: ts_map_key_clear(KEY_SUBTITLE);	break;
+	case 0x050: ts_map_key_clear(KEY_RADIO);	break;
+	case 0x05a: ts_map_key_clear(KEY_TEXT);		break;
+	case 0x05b: ts_map_key_clear(KEY_RED);		break;
+	case 0x05c: ts_map_key_clear(KEY_GREEN);	break;
+	case 0x05d: ts_map_key_clear(KEY_YELLOW);	break;
+	case 0x05e: ts_map_key_clear(KEY_BLUE);		break;
+	default:
+		return 0;
+	}
+
+	return 1;
+}
+
+static const struct hid_device_id ts_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_TOPSEED, USB_DEVICE_ID_TOPSEED_CYBERLINK) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_BTC, USB_DEVICE_ID_BTC_EMPREX_REMOTE) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_BTC, USB_DEVICE_ID_BTC_EMPREX_REMOTE_2) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_TOPSEED2, USB_DEVICE_ID_TOPSEED2_RF_COMBO) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_WIRELESS) },
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_TOSHIBA_WT10A) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, ts_devices);
+
+static struct hid_driver ts_driver = {
+	.name = "topseed",
+	.id_table = ts_devices,
+	.input_mapping = ts_input_mapping,
+};
+module_hid_driver(ts_driver);
+
+MODULE_DESCRIPTION("HID driver for TopSeed Cyberlink remote");
+MODULE_LICENSE("GPL");